1. Field of the Invention
The present invention relates to an information distribution device selection system for selecting one of information distribution devices available on inter-connected communication networks in response to a request from a user terminal device or an information distribution relay device.
2. Description of the Background Art
The conventional information distribution device selection system has been as shown in FIG. 1. Namely, it is a system in which respectively different communication terminal identifiers (individual communication terminal identifiers) are assigned to a plurality of information distribution devices, and they are presented to a user through a user terminal. For example, in FIG. 1, there are three information distribution devices A to C, so that the individual communication terminal identifiers such as [192.0.10.1], [192.0.10.2], [192.0.20.1] are respectively assigned and displayed at the user terminal. In the case where the user makes a connection by selecting a specific information distribution device, the individual communication terminal identifier of the information distribution device may be inputted, but it is also possible to input a code such as "www.nttlabs.com" as an identifier into the user terminal and convert it into the individual communication terminal identifier at a communication terminal identifier search device and the like.
There is also another conventional information distribution device selection system as shown in FIG. 2. In this system, the individual communication terminal identifiers are also assigned respectively to a plurality of information distribution devices, but besides these, information distribution service identifiers (such as keywords in the case of carrying out information retrieval in Internet or database, for example) for indicating the need for selection are also assigned. Then, whether an identifier entered from the user terminal or the information distribution relay device is an individual communication terminal identifier or an information distribution service identifier is judged, and when it is the information distribution service identifier, a database (which is possessed at a communication terminal identifier search device and the like) for making a correspondence between that information distribution service identifier and the individual communication terminal identifier is searched through and at least one individual communication terminal identifier is specific to the user.
In this system, when a plurality of individual communication terminal identifiers are specified while the order of displayed individual communication terminal identifiers is random at each search, the user selects one individual communication terminal identifier that is displayed first and a communication is carried out according to that individual communication terminal identifier.
More specifically, the operation up to the start of communication at the user terminal device according to this system is as shown in the flow chart of FIG. 3. First, whether the information distribution service identifier is entered form the user terminal device or not is judged (step S1), and if so, the processing for searching the individual communication terminal identifier is carried out (step S2). Then, whether there are a plurality of candidates for the individual communication terminal identifier or not is judged (step S3), and if so, one individual communication terminal identifier is selected at the user terminal device (step S4). After the step S4 or when the step S1 or S3 is NO, the communication to the corresponding individual communication terminal identifier is started at the user terminal device (step S5).
In the conventional information distribution device selection system shown in FIG. 2, when at least two or more information distribution devices are to be connected to the identical communication network, it has been necessary to assign individual communication terminal identifiers respectively, and provide information distribution service identifiers in order to make it possible to search these plurality of individual communication terminal identifiers. Then, it has been necessary to carry out the search through a database using the information distribution service identifier entered by the user, and select the individual communication terminal identifier.
Also, there had been cases where, after the user once successfully made a connection to the information distribution device, the user stores the individual communication terminal identifier which has been specified to the user side from the information distribution device selection system by establishing a correspondence from the information distribution service identifier to the individual communication terminal identifier, for the sake of next access occasion.
However, when the user tries to make a connection to the information distribution device at another occasion by using this stored individual communication terminal identifier, there can be cases where the problem arises. For example, there are cases where the connection to that information distribution device cannot be made for the reason such as malfunction of the communication network. There are also cases where the connection to the original information distribution device cannot be made because the information distribution service provider changed the individual communication terminal identifiers of the information distribution device as the information distribution service provider increases or decreases the number of information distribution devices themselves for the reasons including communication amount and cost. There are also cases where the connection cannot be made because that information distribution device itself is malfunctioning. Consequently, the service provider has been unable to change the system freely and the system has been required to have a high reliability.
In such a scheme that provides the information distribution service identifiers to be handled differently from the individual communication terminal identifiers, the correspondence between the information distribution server identifier and the individual communication terminal identifier of the information distribution device for each communication cannot be complete because there are cases in which the user stores the individual communication terminal identifier at a time of actual communication. Also, even if the relationship between the information distribution device and the information distribution service identifier is to be mapped for each communication, there is a need to establish a procedure for communicating the mapping in advance with respect to each communication application, so that it has been difficult to apply this scheme to the existing communication applications.
The problem associated with the conventional information distribution selection system shown in FIG. 2 is that the respective individual communication terminal identifiers are to be provided in order to identify the information distribution devices at a time of connecting a plurality of information distribution devices to the same communication network, while in the case of connecting a new communication network to the inter-connected communication networks, the communication network identifiers which are unique over the entire inter-connected communication networks are to be assigned because the inter-connection is possible only between the communication networks having different communication network identifiers (the individual communication network identifiers), except for the case of constructing the communication network that does not aim at the inter-connection such as closed area network including intra-company network.
Thus the conventional information distribution device selection system has been basically as shown in FIG. 4, where the user terminal device makes a connection with the only one relevant information distribution device through the inter-connected communication networks.
Then, for an information distribution device to which many connection requests occur, there have been two schemes for handling these many connection requests. The first scheme is to provide a plurality of information distribution devices using different communication terminal identifiers at the physically same location in the same communication network. In this scheme, even though these information distribution devices can handle many connection requests, there is a problem that a bandwidth of a channel through which the communication network containing these information distribution devices is connected to the inter-connected communication networks or a congestion state in a route up to that communication network can be a bottleneck.
The second scheme is to provide a plurality of information distribution devices using different communication network identifiers at the physically different locations in different communication networks, as shown in FIG. 5. In this scheme, although it is possible to avoid a congestion in a route up to a communication network containing an information distribution device by providing a plurality of information distribution devices at different communication networks, it is also necessary to provide a means for enabling the user to explicitly select the communication terminal identifier of the information distribution device, or a means for sequentially selecting the communication terminal identifier of the information distribution device at the communication terminal identifier search device, similarly as in the first scheme, so that it does not necessarily realize an optimum (comfortably utilizable) connection from a viewpoint of the user side.